You can find an opponent in three ways. You can simply create a new Game Offer with the custom game button or accept another's Game Offer (displayed in bold in the games lists). You can also use KGS's automatch feature from the "Play Go" menu. The IGS style of issuing direct challenges to another player does not exist on KGS.

You set up the game by creating a Game Offer, using the OK button in
the lower left corner of the "New Game" Window. Both players must agree to the
game conditions which include time limit, handicap, etc. The general process is that the player who creates the Game Offer sets the basic conditions. The player who accepts the Game Offer can change these basic conditions and set other
conditions. The issuer must then accept these changes and additions, although
he may make further changes. When both players have agreed to all the
conditions the game begins and a board is put up in the Playing window for the
players. If there is a condition which you insist on it is a good idea
to type that in the notes area. Then anyone interested in playing you
knows it up front. You can learn more about the specifics in the "New Game" Window help page.

You can chat with your opponent by typing in the chat area at the bottom of
the playing window. Your chat shows up in your opponent's playing window
just above the chat area. All chat is kept in the game record.

If you can't finish the game in one sitting, just leave the game. To be
polite you should tell your opponent what is happening and schedule a later
time to finish the game of course! When you are ready to resume the game,
use the "Resume" button at the top right of the main window to select the desired game to resume. If your opponent is online then that game will be in italics and when you resume the game they will be sent a message inviting them to join the resumed game. You can also resume games where your opponent is not online and thus play "correspondence" go.

The game ends when both players pass. They then tell the server how to
count the game by clicking on dead stones. The server indicates which
intersections are counted as territory by placing dots on them. When all
dead stones have been identified, both players must click on the Done button.
The server announces the score.

The yose needs to be complete before both players pass. If not, then the software can assign huge amounts of territory to the wrong color during the counting phase. The software can not tell where the boundaries between the territories are unless the yose is complete. If this should happen to you, push the undo button. The board is restored to the position before the players passed. Play then proceeds until both players pass again.

If a group is mismarked as dead when it is really alive, shift click on the mismarked group.

After the game the players can review and discuss the game. They can go back to any point in the game and investigate alternate moves. All comments and
variations are kept in the game record. These capabilities can be used for teaching as well.

You can download an SGF file containing the game record to your computer. Click on the Options
button in upper right quadrant of the Game Window. Move the pointer to the "Save To Disk" option and click. You will get a dialog box to select the folder and the
name for the file. The game can be viewed using the CGoban program available
from KGS or any SGF viewer.